So i am getting very close on a backroll but always seem to keep rotating after i land causing me to slide out. Here is a video http://www.youtube.com/watch?v=QNWEe2HD_3A. Vid was shot with an iphone so the quality isn't the best.

One thing that will help you is to take the trick by riding up the wake on edge. The reason you are overrotating has everything to do with you throwing the roll too early. W/out taking the trip you are forced to throw the roll off the wake, otherwise you'll come up short.

One thing I noticed, you flattened off slightly at the trough. This is partly because you are getting ready to throw the roll. Make sure to stand into the wake to get your pop first. This will give you more time to rotate and you will rotate slower. Start there. Take this a little bigger.

As general rule, if you feel that you are overrotating, move the handle toward the flat or at least to the hip closest to the flats. It's tough not to overrotate when you're landing w/ bent knees and just barely getting around. Again, use the wake to take this up that will help to slow you down, as well, because you won't be as focused on throwing the roll so quickly. Give it a run.